December 20, 2008

SOA vs SOI

According to this report by Jack Vaughn at SearchSOA | TechTarget, Yefim Natis asserted "SOA is integration" at last week's Gartner AADI Summit. The assertion produced the usual firestorm of commentary on the Yahoo! SOA discussion list. Michael Poulin started the discussion with this comment:

"What can we do to slow down spreading such Integration SOA madness?"

My response followed suit:

"While I agree with the last line ["SOA is less a technology than a way to dependably extract business value from technology."], I disagree with the leading one: "SOA is integration". Many organizations mistakenly perceive SOA as an integration strategy. But it is not. SOA is about architecture. To achieve SOA, you must rearchitect your systems. You must remove the deadwood. Every organization has too much stuff -- too many redundant applications and data sources. SOA is about cleaning house. You will not simplify your environment, reduce costs, and gain agility until you reduce that redundancy."

We have 17 messages in the thread so far, and our debate was picked up yesterday by Loraine Lawson at ITBusinessEdge. Loraine admonished us for our "boil the ocean" perspective of SOA. As many SOA case studies indicate, "SOA" works well for integration. I put "SOA" into quotes, though, because I assert that these integration case studies are not examples of service oriented architecture (SOA). The are examples of service oriented integration (SOI). i.e., they are examples of projects that used service orientedprotocols (e.g., WS-*) and middleware (e.g., ESB) to integrate two or more application systems. But from an architectural perspective, you still have monolithic systems bridged by integration middleware.

Maybe I'm just being pedantic, but I think it's important to distinguish between integration and architectural activities. It's fine to use service oriented middleware to implement integration projects, but then you need to readjust your expectations. Most organizations that I speak with say that the goals of their SOA initiative are to reduce costs and increase agility. Unfortunately, these organizations aren't likely to achieve these goals if their projects only focus on integration. (Also see Chris Haddad's perspective on these success stories.)

In the research that Chris and I conducted last year, we found only four companies that had achieved real success in their SOA initiatives -- i.e., they met their goals to reduce costs and increase agility. Their successes were astounding, and they delivered positive returns on investment in less than 12 months. In all cases these companies focused on architecture -- not integration.

Service oriented architecture is hard work. It's disruptive. It's a political minefield. It involves going through the application portfolio and identifying redundant applications that can be decommissioned and replaced by a single service. But no one ever wants to open that can of worms. Many folks live by the adage, "If it ain't broke, don't fix it." There's way too much other stuff to do. But each additional application increases the annual maintenance and operations budget. And for many of those applications, the cost of maintaining the application exceeds the value it brings to the business. It's just good business sense to eliminant some of that redundancy. And by the way, the CFO is going to be looking to reduce the IT M&O budget this year. There is no better time to start an application rationalization effort.